This disclosure relates generally to optical communication and, more particularly, to fiber optic connectors having one or more components attached to a ferrule with adhesive.
Over the past several decades, optical fiber has emerged as an alternative to copper wire for transmitting data in a wide variety of industries. Many industries that have traditionally relied on copper to transmit data are increasingly using optical fiber due, at least in part, to the extremely wide bandwidth and low noise associated with optical transmissions. For example, in the consumer electronics industry, short distance data links between electrical devices have reached data rates at which traditional copper cables have limited transmission distance and cable flexibility. Optical cable assemblies are being developed to meet these high demands, especially for devices used in video and storage applications.
Optical cable assemblies include a fiber optic connector on one or both ends of a cable that carries one or more optical fibers. One type of connector used in optical cable assembles for the consumer electronics industry and elsewhere is known as an expanded beam connector, an example of which is schematically illustrated in FIG. 1. In such a fiber optic connector, a ferrule aligns one or more optical fibers 10 with corresponding lens elements 12 provided on or in the ferrule. Each lens element 12 is configured to either: a) receive an optical signal diverging from an end the associated optical fiber positioned within the ferrule and collimate it into an expanded beam for receipt by a corresponding lens element of a mated connector or device, or b) receive an expanded beam of collimated light from a mated corrector or device and focus it into the associated optical fiber positioned within the ferrule.
Expanded beam connectors are typically designed so that the expanded beam travels through an air gap between mated connectors, thereby avoiding physical contact between corresponding lens elements. For example, the ferrule of a connector may be shaped to provide an air pocket or cavity 14 next to the lens elements 12 of the connector. A glass cover (or “window”) 16 is typically positioned on the ferrule over the air cavity 14 because the lens elements 12 of the connector may be subjected to damage and contamination if left exposed and, as a result, negatively affect optical performance. The glass cover 16 is typically bonded to the ferrule using an adhesive. Applying the adhesive requires great care because the glass cover 16 must be precisely positioned without excess adhesive migrating to areas that might result in the adhesive interfering with the optical transmissions. This can be a difficult task due to the limitations of current adhesive dispensing systems.